Method and device for controlling the manufacture of semiconductor by measuring contamination

Abstract

A device for handling substrates within a semiconductor manufacturing plant having substrate processing equipments, substrate storage means, substrate transport means, and a manufacturing execution system (MES) functionally related with the substrate processing equipments, the substrate storage means and the substrate transport means, including at least one substrate storage and transport box that is transported by the transport means and stored in the storage means; at least one gas analysis device of the gases forming the internal atmosphere of the substrate storage and transport box, which produces analysis signals representative of the quantity of the critical gas that is likely to generate molecular contamination, which is present in the storage and transport box; and an execution device which pilots the transport means and the storage means, with the execution device comprising instructions for detecting a molecular decontamination need as a function of analysis signals emitted by the gas analysis device.

The invention claimed is: 
     
       1. A device for handling substrates within a semiconductor manufacturing plant having substrate processing equipment, substrate storage means, substrate transport means, and a manufacturing execution system (MES) functionally related with the substrate processing equipment, with the substrate storage means and with the substrate transport means, comprising:
 at least one substrate storage and transport box that is transported by the transport means and stored in the storage means; 
 at least one internal decontamination station which contains a vacuum when closed in order to internally decontaminate at least one transport and storage box or at least one open, thermal decontamination station containing a vacuum for the open decontamination of at least one empty storage and transport box where the box surfaces are subjected to the combined action of subatmospheric gas pressure and infrared radiation, with the storage and transport box being open, 
 at least one gas analysis means for analyzing the gases forming an internal atmosphere of the substrate storage and transport box, which produces analysis signals representative of the quantity of a critical gas that is able to generate molecular contamination, which is present in the storage and transport box, 
 the gas analysis means being distributed at the output of a substrate processing equipment or integrated into one or more substrate storage means or coupled to one or more decontamination stations, 
 the gas analysis means comprising a gas analysis cell to bring the internal atmosphere of the storage and transport box in contact with a gas analysis cell, where the molecules undergo ionization, in order to analyze their mobility, 
 an execution device which pilots the transport means and the storage means, to selectively directing the storage and transport box to a storage means or to a decontamination station as a function of the result of the gas analysis, the execution device comprising instructions for detecting a molecular decontamination need as a function of analysis signals emitted by the gas analysis device, and wherein if the concentration of at least one critical gas detected by the gas analysis means reaches limits beyond which decontamination or rejected are necessary, the order is given to the transport means to send the substrate storage and transport box either into the substrate storage means or into a reject area or to an open thermal decontamination station. 
 
     
     
       2. A device according to  claim 1 , wherein the execution device is incorporated into the manufacturing execution system (MES). 
     
     
       3. A device according to  claim 1 , wherein a program saved in the execution device contains:
 instructions for producing and scanning the analysis signals, instructions for carrying out a comparison between the analysis signals and recorded threshold values (lim1, lim2, lim3), 
 instructions for piloting the transport means and the storage means depending on the result of this comparison. 
 
     
     
       4. A device according to  claim 3 , wherein:
 the program saved in the execution device further contains instructions for simulating the foreseeable change in contamination within the substrate storage and transport box as a function of analysis signals, 
 the instructions for piloting the transport means and the storage means act as a function of the simulation result. 
 
     
     
       5. A device according to  claim 3 , wherein:
 the device further comprises at least one internal decontamination station which contains a vacuum when closed in order to internally decontaminate at least one transport and storage box, 
 the program saved in the execution device further contains instructions for detecting an internal decontamination need of the storage and transport box and to command the transport means and internal decontamination means in order to ensure the internal decontamination of the storage and transport box. 
 
     
     
       6. A device according to  claim 5 , wherein the program saved in the execution device further contains instructions for ordering the analysis of the gases in a storage and transport box at the outlet of a substrate processing equipment, to convey the storage and transport box to the storage means if the level of a critical gas measured by the gas analysis means, is less than a first predetermined threshold (lim1), and to convey the storage and transport box to the internal decontamination station containing a vacuum if the measured level of critical gas is greater than said first predetermined threshold (lim1). 
     
     
       7. A device according to one of the  claim 1 , comprising:
 at least one open, thermal decontamination station containing a vacuum for the open decontamination of at least one empty storage and transport box, 
 the program saved in the execution device further contains instructions for detecting an open, thermal decontamination need involving a vacuum and for ordering the transport means and open decontamination means in order to ensure the open vacuum decontamination of the storage and transport box, or in order to ensure its quarantining. 
 
     
     
       8. A device according to  claim 7 , wherein the program saved in the execution device further contains instructions for ordering the analysis of the gases in an empty storage and transport box after a waiting time following its being cleaned, to convey the empty storage and transport box into the open, thermal decontamination station containing a vacuum for desorption for a period of time less than 5 hours if the measured level of a critical gas in the storage and transport box is between a second predetermined threshold (lim2) and a third predetermined threshold (lim3), and to convey the storage and transport box into the open, thermal decontamination station containing a vacuum for desorption for a period of time greater than 10 hours if the measured level of critical gas is greater than the third predetermined threshold (lim3). 
     
     
       9. A method for handling substrates within a semiconductor manufacturing plant having substrate processing equipment, substrate storage means, substrate transport means, and a manufacturing execution system (MES) functionally related with the substrate processing equipment, the substrate storage means and the substrate transport means, the method comprising:
 distributing the substrates into batches each contained within a storage and transport box;
 analyzing, via a gas analysis means, the gases forming an internal atmosphere of a storage and transport box and producing analysis signals representative of the quantity of a critical gas that is able to generate molecular contamination which is present in the storage and transport box, bringing the internal atmosphere of the storage and transport box in contact with a gas analysis cell of the gas analysis means, where the molecules undergo ionization, in order to analyze their mobility; 
 
 selectively directing, via an execution device, the storage and transport box to a storage means or to a decontamination station as a function of the result of the gas analysis; and 
 internally decontaminating at least one transport and storage box in the decontamination station which contains a vacuum when closed or internally decontaminating at least one transport and storage box in at least one open, thermal decontamination station containing a vacuum for the open decontamination of at least one empty storage and transport box wherein internally decontaminating comprises subjecting surfaces of an open transport and storage box to the combined action of subatmospheric gas pressure and infrared radiation; and 
 executing, via the execution device, instructions for detecting a molecular decontamination need as a function of analysis signals emitted by the gas analysis means; and 
 in response to the concentration of at least one critical gas detected by the gas analysis means reaching limits beyond which decontamination or rejection are necessary transporting the storage and transport box, via the transport means, into one of: (1) the substrate storage means; or (2) into a reject area; or (3) to the open thermal decontamination station. 
 
     
     
       10. A method according to  claim 9 , wherein the storage and transport box is decontaminated in a vacuum while closed if the measured level of a critical gas in the internal atmosphere of the storage and transport box is greater than a first predetermined threshold (lim1). 
     
     
       11. A method according to  claim 9 , wherein the storage and transport box is decontaminated in a vacuum while open for a period of time less than 5 hours if the measured level of a critical gas in the empty, closed storage and transport box is, after a wait time longer than 2 hours, between a second predetermined threshold (lim2) and a third predetermined threshold (lim3), and for a period of time longer than 10 hours if said measured level of critical gas is greater than the third predetermined threshold (lim3). 
     
     
       12. A method according to  claim 9 , further comprising learning in order to determine permissible limits past which defects may appear in the products manufactured by the method. 
     
     
       13. A method according to  claim 9 , wherein analyzing the gases in the internal atmosphere of a storage and transport box is carried out periodically during its storage in the storage means.